To drive a fastener such as a threaded bolt and a nut, an open-ended wrench, a box-ended wrench, a monkey wrench or a socket wrench may be used. A socket wrench kit includes a handle and a set of sockets of various sizes. In operation, the handle is connected to a selected one of the sockets for driving a fastener of a certain size. Thus, a socket wrench kit can be used to drive fasteners of various sizes. A socket wrench kit is lighter and less expensive than a set of open-ended wrenches or box-ended wrenches. The handle of a socket wrench kit often includes a selective one-way driving mechanism. Therefore, a socket wrench kit is more convenient than a monkey wrench.
It is important to mark the sockets of a socket wrench kit to indicate the sizes of the sockets. There has been an attempt to provide plastic collars of different colors on sockets of different sizes. The plastic collars could easily be blurred, damaged or detached from the sockets so that the sockets would be poorly marked or not marked at all.
Alternatively, indented marks may be made in the sockets by pressing. It however requires an expensive machine to execute the pressing. Moreover, the indented marks are unclear on the sockets. This problem will be even worse when the indented marks are filled with dirt and grease after some time of use.
A socket is generally coated after the pressing. The coating is useful in protecting the socket from rust. The coating is provided on the socket within and outside the indented mark. That is, the color of the socket within the indented mark is identical to the color of the socket outside the indented mark. The coating makes the indented marks more unclear.
There has been another attempt to provide manganese phosphate on a socket after the pressing. The manganese phosphate is useful in protecting the socket from rust. The manganese phosphate however makes the socket look black and blur the indented mark.
Referring to FIGS. 1 and 2, a conventional method for marking a socket 10 is shown. At first, the socket 10 is formed. Secondly, an indented mark 11 is made in the socket 10 by pressing. Thirdly, a coating 16 is provided the socket 10 by electroplating. Fourthly, the socket 10 is ground near the indented mark 11. Fifthly, black dye is provided on the socket 10 near the indented mark 11 so that the indented mark 11 is filled with the black dye. Thus, a black mark 15 is formed in the indented mark 11. Finally, electroplating is done on the socket 10 near the indented mark 11. However, the contrast of the black mark 15 against the socket 10 is not sharp. Therefore, the black mark 15 is not clear. Moreover, black is sometimes undesired for a trademark.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.